An apparatus for determining a position of a first object within a second object is, for example, used in the field of cardiac electrophysiology for localizing the three-dimensional position of a catheter tip within a heart of a patient. These localized three-dimensional positions of the catheter tip are used to record locations of interest such as anatomical landmarks and/or ablation locations in the three-dimensional space. This known localization is based on electro-magnetic or ultrasound real time (low latency) three-dimensional localization techniques. For example, an apparatus for localizing the three-dimensional position of a catheter tip comprises three magnetic field emitting coils, which are arranged close to the patient, and a corresponding sensor on the tip of the catheter, wherein the three-dimensional position of the catheter tip is determined by triangulation measurements.
These known techniques for determining a position of a first object like a catheter tip within a second object like a heart of a patient are complex, require a considerable amount of hardware, in particular specialized catheters, and are, therefore, expensive.